You can see the anim.plots vignette online at github.io. The file size was too large to include in CRAN. If you want to build the vignette yourself, run:
rmd_file <- system.file("doc", "full", "anim.plots.Rmd", package = "anim.plots")
doc_dir <- "path/to/somewhere/appropriate" # e.g. your Desktop folder
rmarkdown::render(rmd_file, clean = FALSE, output_dir = doc_dir)
You can then view it in your web browser.
Be aware that anim.plots is just a simple wrapper around Yihui Xie’s “animation” package. You may want to consider more modern solutions such as gganimate.